COVID Vax During Pregnancy Safe for Infant Brain Development, Study Suggests

— Observational data out to 18 months await confirmation in longer-term follow-up

MedicalToday
A photo of a pregnant woman receiving a COVID vaccination.

COVID-19 vaccination during pregnancy appeared safe for infant neurodevelopment through 18 months of age in a prospective cohort study.

The proportion of 12-month-olds who screened positive for developmental delay was 30.6% among those exposed to the vaccine in utero compared with 28.2% who were unexposed (X2=1.32, P=0.25), reported Eleni Jaswa, MD, MSc, of the University of California San Francisco, and colleagues.

The proportions were likewise similar in screening at 18 months (20.1% vs 23.2%, respectively, X2=2.35, P=0.13), the group .

No differences emerged after adjusting for baseline maternal age, race, ethnicity, education, income, anxiety, and depression (adjusted RR 1.14 at 12 months, 95% CI 0.97-1.33, and 0.88 at 18 months, 95% CI 0.72-1.07). Nor did further adjustments for preterm birth and infant sex affect results at 12 months (aRR 1.16, 95% CI 0.98-1.36) or 18 months (aRR 0.87, 95% CI 0.71-1.07).

The data provide "the first solid evidence basis that COVID vaccination of pregnant patients does not disrupt early childhood development up to 18 months of life for their babies," Jaswa told in an email. "I hope clinicians can feel more comfortable answering questions and addressing concerns that patients may have related to potential risks to their babies."

Longer-term effects of both the virus and interventions directed against it are important to understand as society emerges from the acute phase of the pandemic, Jaswa's group wrote.

And that's true especially for people who were pregnant during the pandemic and their offspring, the researchers noted. "Although pregnancy was identified as a high-risk condition early in the pandemic in light of an increased risk of severe disease and death, considerations surrounding the impact of exposures to the offspring, in the form of infectious agents or countermeasures, remain poorly understood."

They studied a total of 2,487 pregnant individuals with a mean age of 33.3 years enrolled in the nationwide study before 10 weeks' gestation who completed research activities. Ultimately, neurodevelopmental assessments were completed by the birth mothers on 2,261 of their offspring at 12 months of age and 1,940 at 18 months of age using the Ages and Stages Questionnaire, third edition (ASQ-3). A score below the established cutoff in any of five subdomains (communication, gross motor, fine motor, problem solving, or social skills) constituted an abnormal screen.

Overall, males had more abnormal screens for developmental delay than females at 12 months of age (33.2% vs 28.3%, X2=5.57, P=0.02) and at 18 months of age (24.1% vs 19.3%, X2=5.84, P=0.02).

When calculating stratified estimates by sex from a model including interactions between sex, exposure, and age, there was an increased risk of delay among exposed male infants at 12 months of age (aRR 1.29, 95% CI 1.04-1.62). However, the difference was not sustained at 18 months (aRR 1.06, 95% CI 0.80-1.41).

For females, there was no difference in risk of abnormal screens among exposed versus unexposed infants at 12 months of age (aRR 1.02, 95% CI 0.81-1.30) and a reduction in risk observed among exposed infants at age 18 months (aRR 0.69, 95% CI 0.51-0.93).

"Larger studies will be required to explore the sex-specific findings; caution is warranted in interpreting these results," Jaswa and colleagues noted.

Further limitations of the study included that volunteer bias might have affected the distribution of participant characteristics, that imperfect retention may have also contributed to bias, and that the ASQ-3 screening tool requires diagnostic follow-up.

Jaswa and colleagues also noted that, to their knowledge, their study is the "longest follow-up on the topic to date." However, they acknowledged that disturbances in development may manifest later, so prolonged follow-up is required.

"I also hope we are able to continue to follow our ASPIRE [Assessing the Safety of Pregnancy During the Coronavirus Pandemic] study participants for years to come -- it is our obligation as doctors to make sure the clinical guidance provided to our patients and communities is both safe and rooted in good data," Jaswa added.

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    Jennifer Henderson joined as an enterprise and investigative writer in Jan. 2021. She has covered the healthcare industry in NYC, life sciences and the business of law, among other areas.

Disclosures

The study was funded in part by research grants provided to the University of California San Francisco, the Start Small Foundation, California Breast Cancer Research Program, COVID Catalyst Award, AbbVie, Ferring Pharmaceuticals, University of California, and individual philanthropists.

Jaswa reported receiving grants from the California Breast Cancer Research Program and the Start Small Foundation during the conduct of the study. Co-authors reported receiving grants from the Reproductive Medicine Network and the National Institute of Allergy and Infectious Diseases.

Primary Source

JAMA Pediatrics

Jaswa EG, et al "In utero exposure to maternal COVID-19 vaccination and offspring neurodevelopment at 12 and 18 months" JAMA Pediatr 2024; DOI: 10.1001/jamapediatrics.2023.5743.